#include "AES.h"
#include <string.h>

#ifdef _AES_DEBUG_
#include <stdarg.h>
void debug(StateAES* state, char* fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	vfprintf(state->LogFile, fmt, args);
	va_end(args);
}
void PrintBuffer(StateAES* state)
{
	unsigned int temp;
	int i;
	unsigned char* arr = state->Buffer;
	for (i = 0; i < 16; i++)
	{
		temp = arr[i];
		fprintf(state->LogFile, "%.2x", temp);
		if ((i + 1) % 8 == 0)
		{
			fprintf(state->LogFile, "\n");
		}
	}
}
int AES_SetLogFile(StateAES* state, FILE* logFile)
{
	if (logFile == NULL)
	{
		logFile = stdout; // reset the output file
	}
	state->LogFile = logFile;
	return 0;
}
#else
#define PrintArray
#define debug
#endif

static unsigned char _sBox[256] = {
	0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
	0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
	0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
	0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
	0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
	0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
	0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
	0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
	0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
	0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
	0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
	0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
	0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
	0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
	0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
	0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16
};
static unsigned char _isBox[256] = {
	0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
	0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
	0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
	0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
	0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
	0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
	0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
	0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
	0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
	0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
	0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
	0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
	0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
	0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
	0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
	0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
};
static unsigned char _logTable[256] = {
	0x0, 0xff, 0x19, 0x1, 0x32, 0x2, 0x1a, 0xc6, 0x4b, 0xc7, 0x1b, 0x68, 0x33, 0xee, 0xdf, 0x3, 0x64, 0x4, 0xe0, 0xe, 0x34, 0x8d, 0x81, 0xef, 0x4c, 0x71, 0x8, 0xc8, 0xf8, 0x69, 0x1c, 0xc1,
	0x7d, 0xc2, 0x1d, 0xb5, 0xf9, 0xb9, 0x27, 0x6a, 0x4d, 0xe4, 0xa6, 0x72, 0x9a, 0xc9, 0x9, 0x78, 0x65, 0x2f, 0x8a, 0x5, 0x21, 0xf, 0xe1, 0x24, 0x12, 0xf0, 0x82, 0x45, 0x35, 0x93, 0xda, 0x8e,
	0x96, 0x8f, 0xdb, 0xbd, 0x36, 0xd0, 0xce, 0x94, 0x13, 0x5c, 0xd2, 0xf1, 0x40, 0x46, 0x83, 0x38, 0x66, 0xdd, 0xfd, 0x30, 0xbf, 0x6, 0x8b, 0x62, 0xb3, 0x25, 0xe2, 0x98, 0x22, 0x88, 0x91, 0x10,
	0x7e, 0x6e, 0x48, 0xc3, 0xa3, 0xb6, 0x1e, 0x42, 0x3a, 0x6b, 0x28, 0x54, 0xfa, 0x85, 0x3d, 0xba, 0x2b, 0x79, 0xa, 0x15, 0x9b, 0x9f, 0x5e, 0xca, 0x4e, 0xd4, 0xac, 0xe5, 0xf3, 0x73, 0xa7, 0x57,
	0xaf, 0x58, 0xa8, 0x50, 0xf4, 0xea, 0xd6, 0x74, 0x4f, 0xae, 0xe9, 0xd5, 0xe7, 0xe6, 0xad, 0xe8, 0x2c, 0xd7, 0x75, 0x7a, 0xeb, 0x16, 0xb, 0xf5, 0x59, 0xcb, 0x5f, 0xb0, 0x9c, 0xa9, 0x51, 0xa0,
	0x7f, 0xc, 0xf6, 0x6f, 0x17, 0xc4, 0x49, 0xec, 0xd8, 0x43, 0x1f, 0x2d, 0xa4, 0x76, 0x7b, 0xb7, 0xcc, 0xbb, 0x3e, 0x5a, 0xfb, 0x60, 0xb1, 0x86, 0x3b, 0x52, 0xa1, 0x6c, 0xaa, 0x55, 0x29, 0x9d,
	0x97, 0xb2, 0x87, 0x90, 0x61, 0xbe, 0xdc, 0xfc, 0xbc, 0x95, 0xcf, 0xcd, 0x37, 0x3f, 0x5b, 0xd1, 0x53, 0x39, 0x84, 0x3c, 0x41, 0xa2, 0x6d, 0x47, 0x14, 0x2a, 0x9e, 0x5d, 0x56, 0xf2, 0xd3, 0xab,
	0x44, 0x11, 0x92, 0xd9, 0x23, 0x20, 0x2e, 0x89, 0xb4, 0x7c, 0xb8, 0x26, 0x77, 0x99, 0xe3, 0xa5, 0x67, 0x4a, 0xed, 0xde, 0xc5, 0x31, 0xfe, 0x18, 0xd, 0x63, 0x8c, 0x80, 0xc0, 0xf7, 0x70, 0x7
};
static unsigned char _alogTable[256] = {
	0x1, 0x3, 0x5, 0xf, 0x11, 0x33, 0x55, 0xff, 0x1a, 0x2e, 0x72, 0x96, 0xa1, 0xf8, 0x13, 0x35, 0x5f, 0xe1, 0x38, 0x48, 0xd8, 0x73, 0x95, 0xa4, 0xf7, 0x2, 0x6, 0xa, 0x1e, 0x22, 0x66, 0xaa,
	0xe5, 0x34, 0x5c, 0xe4, 0x37, 0x59, 0xeb, 0x26, 0x6a, 0xbe, 0xd9, 0x70, 0x90, 0xab, 0xe6, 0x31, 0x53, 0xf5, 0x4, 0xc, 0x14, 0x3c, 0x44, 0xcc, 0x4f, 0xd1, 0x68, 0xb8, 0xd3, 0x6e, 0xb2, 0xcd,
	0x4c, 0xd4, 0x67, 0xa9, 0xe0, 0x3b, 0x4d, 0xd7, 0x62, 0xa6, 0xf1, 0x8, 0x18, 0x28, 0x78, 0x88, 0x83, 0x9e, 0xb9, 0xd0, 0x6b, 0xbd, 0xdc, 0x7f, 0x81, 0x98, 0xb3, 0xce, 0x49, 0xdb, 0x76, 0x9a,
	0xb5, 0xc4, 0x57, 0xf9, 0x10, 0x30, 0x50, 0xf0, 0xb, 0x1d, 0x27, 0x69, 0xbb, 0xd6, 0x61, 0xa3, 0xfe, 0x19, 0x2b, 0x7d, 0x87, 0x92, 0xad, 0xec, 0x2f, 0x71, 0x93, 0xae, 0xe9, 0x20, 0x60, 0xa0,
	0xfb, 0x16, 0x3a, 0x4e, 0xd2, 0x6d, 0xb7, 0xc2, 0x5d, 0xe7, 0x32, 0x56, 0xfa, 0x15, 0x3f, 0x41, 0xc3, 0x5e, 0xe2, 0x3d, 0x47, 0xc9, 0x40, 0xc0, 0x5b, 0xed, 0x2c, 0x74, 0x9c, 0xbf, 0xda, 0x75,
	0x9f, 0xba, 0xd5, 0x64, 0xac, 0xef, 0x2a, 0x7e, 0x82, 0x9d, 0xbc, 0xdf, 0x7a, 0x8e, 0x89, 0x80, 0x9b, 0xb6, 0xc1, 0x58, 0xe8, 0x23, 0x65, 0xaf, 0xea, 0x25, 0x6f, 0xb1, 0xc8, 0x43, 0xc5, 0x54,
	0xfc, 0x1f, 0x21, 0x63, 0xa5, 0xf4, 0x7, 0x9, 0x1b, 0x2d, 0x77, 0x99, 0xb0, 0xcb, 0x46, 0xca, 0x45, 0xcf, 0x4a, 0xde, 0x79, 0x8b, 0x86, 0x91, 0xa8, 0xe3, 0x3e, 0x42, 0xc6, 0x51, 0xf3, 0xe,
	0x12, 0x36, 0x5a, 0xee, 0x29, 0x7b, 0x8d, 0x8c, 0x8f, 0x8a, 0x85, 0x94, 0xa7, 0xf2, 0xd, 0x17, 0x39, 0x4b, 0xdd, 0x7c, 0x84, 0x97, 0xa2, 0xfd, 0x1c, 0x24, 0x6c, 0xb4, 0xc7, 0x52, 0xf6, 0x1
};

unsigned char GMul(unsigned char, unsigned char);
unsigned long SubWord(unsigned long);
unsigned long RotWord(unsigned long);
void AddRoundKey(StateAES*, int);
void SubBytes(StateAES*);
void ShiftRows(StateAES*);
void MixCols(StateAES*);
void InverseShiftRows(StateAES*);
void InverseSubBytes(StateAES*);
void InverseMixCols(StateAES*);
void TransposeState(StateAES*);

int AES_Init(StateAES* state, unsigned char key[16])
{
	static const unsigned long rcon[10] = {
		0x01000000, 0x02000000, 0x04000000, 0x08000000,
		0x10000000, 0x20000000, 0x40000000, 0x80000000,
		0x1B000000, 0x36000000
	};
	unsigned long temp;
	int Nk, Nr, i, j;
	unsigned long* w = state->KeyExpansion;
	memset(state, 0, sizeof(StateAES));
	memcpy(state->Key, key, 16);
	Nr = 10;
	Nk = Nr - 6;
	for (i = 0, j = 0; j < Nk; j++, i += 4)
	{
		w[j] = (unsigned long)((key[i] << 24) | (key[i + 1] << 16) | (key[i + 2] << 8) | (key[i + 3]));
	}
	for (i = Nk; i < (4 * (Nr + 1)); i++)
	{
		temp = w[i - 1];
		if (i % Nk == 0)
		{
			temp = SubWord(RotWord(temp)) ^ rcon[(i / Nk) - 1];
		}
		w[i] = w[i - Nk] ^ temp;
	}
	return 0; // no error;
}

int AES_Encrypt(StateAES* state, unsigned char block[16])
{
	int Nr = 10, i = 0;
	memcpy(state->Buffer, block, 16);
	TransposeState(state);
	AddRoundKey(state, 0);
	for (i = 1; i < Nr; i++)
	{
		SubBytes(state);
		ShiftRows(state);
		MixCols(state);
		AddRoundKey(state, i);
	}
	SubBytes(state);
	ShiftRows(state);
	AddRoundKey(state, Nr);
	TransposeState(state);
	return 0;
}

int AES_Decrypt(StateAES* state, unsigned char block[16])
{
	int Nr = 10, i = 0;
	memcpy(state->Buffer, block, 16);
	TransposeState(state);
	AddRoundKey(state, Nr);
	for (i = Nr - 1; i > 0; i--)
	{
		InverseShiftRows(state);
		InverseSubBytes(state);
		AddRoundKey(state, i);
		InverseMixCols(state);
	}
	InverseShiftRows(state);
	InverseSubBytes(state);
	AddRoundKey(state, 0);
	TransposeState(state);
	return 0;
}

int AES_Final(StateAES* state, unsigned char out[16])
{
	memcpy(out, state->Buffer, 16);
	return 0;
}

unsigned long SubWord(unsigned long word)
{
	unsigned long t = 0;
	t |= (unsigned long)((_sBox[(word >> 24) & 0xFF]) << 24);
	t |= (unsigned long)((_sBox[(word >> 16) & 0xFF]) << 16);
	t |= (unsigned long)((_sBox[(word >> 8) & 0xFF]) << 8);
	t |= (unsigned long)((_sBox[word & 0xFF]));
	return t;
}

unsigned long RotWord(unsigned long word)
{
	return (unsigned long)((word << 8) | (word >> 24));
}

void AddRoundKey(StateAES* state, int roundNum)
{
	unsigned long col = 0;
	int i = 0;
	for (i = 0; i < 4; i++)
	{
		col = (unsigned long)((state->Buffer[i] << 24) | (state->Buffer[i + 4] << 16) | (state->Buffer[i + 8] << 8) | (state->Buffer[i + 12]));
		col ^= state->KeyExpansion[(roundNum * 4) + i];
		state->Buffer[i] = (unsigned char)(col >> 24);
		state->Buffer[i + 4] = (unsigned char)((col >> 16) & 0xFF);
		state->Buffer[i + 8] = (unsigned char)((col >> 8) & 0xFF);
		state->Buffer[i + 12] = (unsigned char)(col & 0xFF);
	}
}

void SubBytes(StateAES* state)
{
	unsigned char* b = state->Buffer;
	int i;
	for (i = 0; i < 16; i++)
	{
		b[i] = _sBox[b[i]];
	}
}

void ShiftRows(StateAES* state)
{
	unsigned char temp0, temp1, temp2, *k = state->Buffer;
	temp0 = k[4];
	k[4] = k[5];
	k[5] = k[6];
	k[6] = k[7];
	k[7] = temp0;
	temp0 = k[8];
	temp1 = k[9];
	k[8] = k[10];
	k[9] = k[11];
	k[10] = temp0;
	k[11] = temp1;
	temp0 = k[12];
	temp1 = k[13];
	temp2 = k[14];
	k[12] = k[15];
	k[13] = temp0;
	k[14] = temp1;
	k[15] = temp2;
}

void MixCols(StateAES* state)
{
	unsigned char a[4], b[4], *k = state->Buffer;
	int i = 0;
	for (i = 0; i < 4; i++)
	{
		a[0] = k[i];
		a[1] = k[i + 4];
		a[2] = k[i + 8];
		a[3] = k[i + 12];
		b[0] = GMul(a[0], 2) ^ GMul(a[1], 3) ^ a[2] ^ a[3];
		b[1] = GMul(a[1], 2) ^ GMul(a[2], 3) ^ a[3] ^ a[0];
		b[2] = GMul(a[2], 2) ^ GMul(a[3], 3) ^ a[0] ^ a[1];
		b[3] = GMul(a[3], 2) ^ GMul(a[0], 3) ^ a[1] ^ a[2];
		k[i] = b[0];
		k[i + 4] = b[1];
		k[i + 8] = b[2];
		k[i + 12] = b[3];
	}
}

void InverseShiftRows(StateAES* state)
{
	unsigned char temp0, temp1, temp2, *k = state->Buffer;
	temp0 = k[7];
	k[7] = k[6];
	k[6] = k[5];
	k[5] = k[4];
	k[4] = temp0;
	temp0 = k[11];
	temp1 = k[10];
	k[11] = k[9];
	k[10] = k[8];
	k[9] = temp0;
	k[8] = temp1;
	temp0 = k[15];
	temp1 = k[14];
	temp2 = k[13];
	k[15] = k[12];
	k[14] = temp0;
	k[13] = temp1;
	k[12] = temp2;
}

void InverseSubBytes(StateAES* state)
{
	int i;
	for (i = 0; i < 16; i++)
	{
		state->Buffer[i] = _isBox[state->Buffer[i]];
	}
}

void InverseMixCols(StateAES* state)
{
	unsigned char a[4], b[4], *k = state->Buffer;
	int i = 0;
	for (i = 0; i < 4; i++)
	{
		a[0] = k[i];
		a[1] = k[i + 4];
		a[2] = k[i + 8];
		a[3] = k[i + 12];
		b[0] = GMul(a[0], 14) ^ GMul(a[1], 11) ^ GMul(a[2],13) ^ GMul(a[3],9);
		b[1] = GMul(a[1], 14) ^ GMul(a[2], 11) ^ GMul(a[3],13) ^ GMul(a[0],9);
		b[2] = GMul(a[2], 14) ^ GMul(a[3], 11) ^ GMul(a[0],13) ^ GMul(a[1],9);
		b[3] = GMul(a[3], 14) ^ GMul(a[0], 11) ^ GMul(a[1],13) ^ GMul(a[2],9);
		k[i] = b[0];
		k[i + 4] = b[1];
		k[i + 8] = b[2];
		k[i + 12] = b[3];
	}
}

void TransposeState(StateAES* state)
{
	unsigned char* k = state->Buffer, temp[16];
	int row, col;
	memcpy(temp, k, 16);
	for (row = 0; row < 4; row++)
	{
		for (col = 0; col < 4; col++)
		{
			k[(row * 4) + col] = temp[(col * 4) + row];
		}
	}
}

unsigned char GMul(unsigned char a, unsigned char b)
{
	unsigned char ret = 0;
	if (a == 0 || b == 0)
	{
		ret = 0;
	}
	else
	{
		ret = _alogTable[((int)(_logTable[a] + _logTable[b])) % 255];
	}
	return ret;
}
